Integrated transmit/receive switch

ABSTRACT

An apparatus comprises a transmit network to transmit an input from a first amplifier to an antenna, a receive network to provide an input from an antenna to a second amplifier, a first switch to selectively decouple the transmit network from the antenna, and a second switch to selectively decouple the receive network from the antenna. Other embodiments may be described.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/949,008, filed on Nov. 18, 2010, entitled “INTEGRATEDTRANSMIT/RECEIVE SWITCH”, which is hereby incorporated herein byreference in its entirety and for all purposes.

BACKGROUND

The subject matter described herein relates generally to the field ofelectronic communication and more particularly to transmit/receiveswitches which may be used in electronic devices.

Many electronic devices such as notebook and laptop computers, personaldigital assistants (PDAs), and the like include one or more wirelesstransceivers to send and receive data via wireless networks. Multi-modedevices, which can transceiver data on multiple different wirelessnetworks, may share hardware, e.g., transmitters, receivers, antennas,etc., in order to reduce both the cost and size of a device. Further, insome modulation schemes the transmitter operates on one frequency andthe receiver operates on a separate frequency, and a duplexer may beused to separate the frequencies. In a time-duplex-division scheme thetransmission and receive functions may be separated in time.

These schemes may utilize a switching device to switch a transceiverbetween a transmit mode and a receive mode. Accordingly, switchingarrangements in a wireless transceiver may find utility.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures.

FIGS. 1A-1C are schematic illustrations of a power amplifier moduleincluding an integrated transmit/receive switching module in accordancewith some embodiments.

FIG. 2 is a schematic illustration of components of an electronicdevice, according to embodiments.

FIG. 3 is a schematic illustration of a wireless device according tosome embodiments.

FIG. 4 is a schematic illustration of a system which may be adapted toimplement thermal management, according to an embodiment.

FIG. 5 is a schematic illustration of a wireless networking environment,according to some embodiments.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a thorough understanding of various embodiments. However, itwill be understood by those skilled in the art that the variousembodiments may be practiced without the specific details. In otherinstances, well-known methods, procedures, components, and circuits havenot been illustrated or described in detail so as not to obscure theparticular embodiments.

FIGS. 1A-1C are schematic illustrations of a power amplifier module 102a low noise amplifier 170 and an integrated transmit/receive switchingmodule 110. Referring to FIG. 1A, in some embodiments a transmit/receivemodule 100 includes a power amplifier 102, a switching and matchingmodule 110, and a low noise amplifier 170. The first amplifier 102 maybe embodied as power amplifier to amplify an input electrical signal. Aswitching and matching module 110 is coupled to the first amplifier 102to deliver a signal from the power amplifier 102 to the antenna 130, andis coupled to a low noise amplifier 170, which receives an output signalfrom the switching and matching module 110. Switching and matchingmodule 110 is also coupled to one or more antennas 130. In theembodiment depicted in FIG. 1A the switching and matching module 110 iscoupled to antenna 130 via an inductive link. One skilled in the artwill recognize that the switching and matching module 110 may be coupledto antenna 130 via other types of links, e.g., via a direct electricalconnection to antenna 130.

In the embodiment depicted in FIG. 1A the switching and matching module110 comprises a transmit network 120 and a receive network 140. Thetransmit network 120 couples the power amplifier 102 to the antenna 130,such that electrical signals output from the power amplifier 102 may betransmitted via antenna 130. The receive network 140 couples the antenna130 to the low noise amplifier 170, such that electromagnetic signalsreceived by antenna 130 may be deliver to the low noise amplifier 170.

In some embodiments the transmit network 120 comprises a first line 122and a second line 124 coupled to respective first and second outputs ofthe first amplifier 102. The transmit network 120 and the receivenetwork 140 are connected together to the differential input/output 132.The differential input/output 132 is connected to an antenna via a balun134 which provides an inductive link between antenna 130 and both thetransmit network 120 and the receive network 140.

The transmit network 120 comprises a first switch 126 that provides anelectrical connection of capacitors between the first line 122 and thesecond line 124. The first switch 126 is positioned between theinductive link of the transformer 118 and the first amplifier 102. Thefirst switch 126 is connected to the first line 122 and the second line124 via capacitors C.

In some embodiments the receive network 140 comprises a third line 142and fourth line 144 to couple to the antenna 130. An inductor 148 isconnected to the third line 142 and fourth line 144. A capacitor C isdisposed on each of the first line 142 and the second line 144 and asecond switch 146 selectively connecting the capacitors C together.

In the embodiment depicted in FIG. 1A the receive network 140 is coupledto the low noise amplifier 170 via a second transformer 148, whichestablishes an inductive link between line 143 and line 145 and a line152 and line 164, respectively. The fifth line 152 and sixth line 154are input into the low noise amplifier 170. A switch 156 couples thefifth line 152 to ground and a switch 158 couples the sixth line 154 toground.

Having described the structural components of the switching and matchingmodule 110, attention will now to a description of operations of theswitching and matching module 110. In some embodiments switching andmatching module 110 operates to switch between a transmit state in whichthe transmit network is coupled to antenna 130 and a receive state inwhich the receive network 140 is coupled to antenna 130.

FIG. 1B is a schematic illustration of the transmit/receive module 100with switching and matching module 110 in a transmit state. Referring toFIG. 1B, in a transmit state the switch 146 is closed to connect lines143 and 145. Closing switch 146 establishes an RLC circuit in thereceive network 140 such that the receive network 140 presents aparallel resonance load (i.e., high impedance) at the band frequency ofthe switching and matching module, thereby effectively decoupling thereceive network 140 from the antenna 130. Thus, signals input from thepower amplifier 102 are transmitted across the transmit network 120 tothe antenna 130.

In addition, switches 156 and 158 may be closed, which connects thesecond amplifier 170 to ground. This isolates the receive network 140from the transmit network 120, reduces transmission insertion loss, andreduces signal swing at the input to the low noise amplifier 170.

FIG. 1C is a schematic illustration of the transmit/receive module 100with the switching and matching module 110 in a receive state. Referringto FIG. 1C, in a receive state the switch 126 is closed to connect lines122 and 124 thru two capacitors. Closing switch 126 establishes an RCLcircuit in the transmit network 120 such that the transmit network 120presents a parallel resonance load (i.e., high impedance) at the bandfrequency of the switching and matching module 110, thereby effectivelydecoupling the transmit network 120 from the antenna 130.

The switches 126 and 146 define logic to switch the switching andmatching module 110 between a transmit state and a receive state.Switches 156 and 158 may also be considered part of the logic to switchthe switching and matching module 110 between a transmit state and areceive state as these switches improve the overall switchingperformance, although they are not necessary for the operation ofswitching and matching module 110.

In some embodiments the switching and matching module 110 may beincorporated into the RF communication capability 200 of an electronicdevice. Referring now to FIG. 2, a block diagram of an RF communicationcapability 200 in accordance with one or more embodiments will bediscussed. FIG. 2 depicts the major elements of an RF communicationcapability 200, however fewer or additional elements may be included inalternative embodiments in addition to various other elements that arenot shown herein, and the scope of the claimed subject matter is notlimited in these respects.

RF communication capability 200 may comprise a baseband processor 210coupled to memory 212 for performing the control functions of RFcommunication capability. Input/output (I/O) block 214 may comprisevarious circuits for coupling RF communication capability to one or moreother devices or components of an electronic device. For example, I/Oblock 214 may include one or more Ethernet ports and/or one or moreuniversal serial bus (USB) ports for coupling RF communicationcapability 200 to a modem or other devices. For wireless communication,RF communication capability 200 may further include a radio-frequency(RF) modulator/demodulator 220 for modulating signals to be transmittedand/or for demodulating signals received via a wireless communicationlink.

A digital-to-analog (D/A) converter 216 may convert digital signals frombaseband processor 210 to analog signals for modulation and broadcastingby RF modulator/demodulator 220 via analog and/or digital RFtransmission techniques. Likewise, analog-to-digital (A/D) converter 218may convert analog signals received and demodulated by RFmodulator/demodulator 220 digital signals in a format capable of beinghandled by baseband processor 210. Power amplifier (PA) 222 transmitsoutgoing signals via one or more antennas 228 and/or 230, and low noiseamplifier (LNA) 224 receives one or more incoming signals via antennas228 and/or 230, which may be coupled via switching and matching module110 as depicted in FIGS. 1A-1C to control such bidirectionalcommunication. In one or more embodiments, RF communication capability200 may implement single input, single output (SISO) type communication,and in one or more alternative embodiments RF communication capabilitymay implement multiple input, multiple output (MIMO) communications,although the scope of the claimed subject matter is not limited in theserespects.

FIG. 3 is a schematic illustration of an electronic device 316 whichincludes a wireless communication capability, according to someembodiments. Referring to FIG. 3, in some embodiments electronic device316 may be embodied as a mobile telephone, a personal digital assistant(PDA), a laptop computer, or the like. Electronic device 316 may includean RF transceiver 350 to transceive RF signals and a signal processingmodule 352 to process signals received by RF transceiver 350.

RF transceiver 350 may implement a local wireless connection via aprotocol such as, e.g., Bluetooth or 802.11x. IEEE 802.11a, b org-compliant interface (see, e.g., IEEE Standard forIT-Telecommunications and information exchange between systemsLAN/MAN—Part II: Wireless LAN Medium Access Control (MAC) and PhysicalLayer (PHY) specifications Amendment 4: Further Higher Data RateExtension in the 2.4 GHz Band, 802.11G-2003). Another example of awireless interface would be a general packet radio service (GPRS)interface (see, e.g., Guidelines on GPRS Handset Requirements, GlobalSystem for Mobile Communications/GSM Association, Ver. 3.0.1, December2002).

Electronic device 316 may further include one or more processors 354 anda memory module 356. As used herein, the term “processor” means any typeof computational element, such as but not limited to, a microprocessor,a microcontroller, a complex instruction set computing (CISC)microprocessor, a reduced instruction set (RISC) microprocessor, a verylong instruction word (VLIW) microprocessor, or any other type ofprocessor or processing circuit. In some embodiments, processor 354 maybe one or more processors in the family of Intel® PXA27x processorsavailable from Intel® Corporation of Santa Clara, Calif. Alternatively,other CPUs may be used, such as Intel's Itanium®, XEON™, ATOM™, andCeleron® processors. Also, one or more processors from othermanufactures may be utilized. Moreover, the processors may have a singleor multi core design. In some embodiments, memory module 356 includesrandom access memory (RAM); however, memory module 356 may beimplemented using other memory types such as dynamic RAM (DRAM),synchronous DRAM (SDRAM), and the like.

Electronic device 316 may further include one or more input/outputinterfaces such as, e.g., a keypad 358 and one or more displays 360. Insome embodiments electronic device 316 comprises one or more cameramodules 362 and an image signal processor 364.

FIG. 4 is a schematic illustration of a computer system 400 which mayinclude a wireless communication capability in accordance with someembodiments. The computer system 400 includes a computing device 402 anda power adapter 404 (e.g., to supply electrical power to the computingdevice 402). The computing device 402 may be any suitable computingdevice such as a laptop (or notebook) computer, a personal digitalassistant, a desktop computing device (e.g., a workstation or a desktopcomputer), a rack-mounted computing device, and the like.

Electrical power may be provided to various components of the computingdevice 402 (e.g., through a computing device power supply 406) from oneor more of the following sources: one or more battery packs, analternating current (AC) outlet (e.g., through a transformer and/oradaptor such as a power adapter 404), automotive power supplies,airplane power supplies, and the like. In some embodiments, the poweradapter 404 may transform the power supply source output (e.g., the ACoutlet voltage of about 110 VAC to 240 VAC) to a direct current (DC)voltage ranging between about 7 VDC to 12.6 VDC. Accordingly, the poweradapter 404 may be an AC/DC adapter.

The computing device 402 may also include one or more central processingunit(s) (CPUs) 408. In some embodiments, the CPU 408 may be one or moreprocessors in the Pentium® family of processors including the Pentium®II processor family, Pentium® III processors, Pentium® IV, or CORE2 Duoprocessors available from Intel® Corporation of Santa Clara, Calif.Alternatively, other CPUs may be used, such as Intel's Itanium®, XEON™,and Celeron® processors. Also, one or more processors from othermanufactures may be utilized. Moreover, the processors may have a singleor multi core design.

A chipset 412 may be coupled to, or integrated with, CPU 408. Thechipset 412 may include a memory control hub (MCH) 414. The MCH 414 mayinclude a memory controller 416 that is coupled to a main system memory418. The main system memory 418 stores data and sequences ofinstructions that are executed by the CPU 408, or any other deviceincluded in the system 400. In some embodiments, the main system memory418 includes random access memory (RAM); however, the main system memory418 may be implemented using other memory types such as dynamic RAM(DRAM), synchronous DRAM (SDRAM), and the like. Additional devices mayalso be coupled to the bus 410, such as multiple CPUs and/or multiplesystem memories.

The MCH 414 may also include a graphics interface 420 coupled to agraphics accelerator 422. In some embodiments, the graphics interface420 is coupled to the graphics accelerator 422 via an acceleratedgraphics port (AGP). In some embodiments, a display (such as a flatpanel display) 440 may be coupled to the graphics interface 420 through,for example, a signal converter that translates a digital representationof an image stored in a storage device such as video memory or systemmemory into display signals that are interpreted and displayed by thedisplay. The display 440 signals produced by the display device may passthrough various control devices before being interpreted by andsubsequently displayed on the display.

A hub interface 424 couples the MCH 414 to a platform control hub (PCH)426. The PCH 426 provides an interface to input/output (I/O) devicescoupled to the computer system 400. The PCH 426 may be coupled to aperipheral component interconnect (PCI) bus. Hence, the PCH 426 includesa PCI bridge 428 that provides an interface to a PCI bus 430. The PCIbridge 428 provides a data path between the CPU 408 and peripheraldevices. Additionally, other types of I/O interconnect topologies may beutilized such as the PCI Express™ architecture, available through Intel®Corporation of Santa Clara, Calif.

The PCI bus 430 may be coupled to an audio device 432 and one or moredisk drive(s) 434. Other devices may be coupled to the PCI bus 430. Inaddition, the CPU 408 and the MCH 414 may be combined to form a singlechip. Furthermore, the graphics accelerator 422 may be included withinthe MCH 414 in other embodiments.

Additionally, other peripherals coupled to the PCH 426 may include, invarious embodiments, integrated drive electronics (IDE) or smallcomputer system interface (SCSI) hard drive(s), universal serial bus(USB) port(s), a keyboard, a mouse, parallel port(s), serial port(s),floppy disk drive(s), digital output support (e.g., digital videointerface (DVI)), and the like. Hence, the computing device 402 mayinclude volatile and/or nonvolatile memory.

FIG. 5 is a schematic illustration of a wireless networking environment,according to some embodiments. Referring to FIG. 5, a block diagram of awireless wide area network in accordance with one or more embodimentswill be discussed. As shown in FIG. 5, network 500 may be an internetprotocol (IP) type network comprising an Internet 510 type network orthe like that is capable of supporting mobile wireless access and/orfixed wireless access to internet 510. In one or more embodiments,network 500 may be in compliance with a Worldwide Interoperability forMicrowave Access (WiMAX) standard or future generations of WiMAX, and inone particular embodiment may be in compliance with an Institute forElectrical and Electronics Engineers 802.16 standard (IEEE 802.16-2009).In one or more alternative embodiments network 500 may be in compliancewith a Third Generation Partnership Project Long Term Evolution (3GPPLTE) or a 3GPP2 Air Interface Evolution (3GPP2 AIE) standard, and/or afuture generation cellular broadband network standard. In general,network 500 may comprise any type of orthogonal frequency divisionmultiple access (OFDMA) based wireless network, and the scope of theclaimed subject matter is not limited in these respects. As an exampleof mobile wireless access, access service network gateway (ASN-GW) 512is capable of coupling with base station (BS) 514 to provide wirelesscommunication between wireless device (SS) 516 and Internet 510.Wireless device 516 may comprise a mobile type device or informationhandling system capable of wirelessly communicating via network 500, forexample a notebook type computer, a cellular telephone, a personaldigital assistant, or the like. ASN-GW 512 may implement profiles thatare capable of defining the mapping of network functions to one or morephysical entities on network 500. Base station 514 may comprise radioequipment to provide radio-frequency (RF) communication with wirelessdevice 516, and may comprise, for example, the physical layer (PHY) andmedia access control (MAC) layer equipment in compliance with an IEEE802.16-2009 type standard. Alternatively, base station 512 may also bereferred to as a base transceiver station (BTS) in one or moreembodiments. Base station 514 may further comprise an IP backplane tocouple to Internet 510 via ASN-GW 512, although the scope of the claimedsubject matter is not limited in these respects.

Network 500 may further comprise a visited connectivity servicenetwork/authentication, authorization, and accounting (CSN/AAA) server524 capable of providing one or more network functions including but notlimited to proxy and/or relay type functions, for exampleauthentication, authorization and accounting (AAA) functions, dynamichost configuration protocol (DHCP) functions, or domain name servicecontrols or the like, domain gateways such as public switched telephonenetwork (PSTN) gateways or voice over internet protocol (VOIP) gateways,and/or internet protocol (IP) type server functions, or the like.However, these are merely example of the types of functions that arecapable of being provided by visited CSN/AAA or home CSN/AAA 526, andthe scope of the claimed subject matter is not limited in theserespects. Visited CSN/AAA 524 may be referred to as a visited CSN/AAA inthe case for example where visited CSN/AAA 524 is not part of theregular service provider of wireless device 516, for example wherewireless device 516 is roaming away from its home CSN/AAA such as homeCSN/AAA 526, or for example where network 500 is part of the regularservice provider of wireless device but where network 500 may be inanother location or state that is not the main or home location ofwireless device 516. In a fixed wireless arrangement, WiMAX typecustomer premises equipment (CPE) 522 may be located in a home orbusiness to provide home or business customer broadband access tointernet 510 via base station 520, ASN-GW 518, and home CSN/AAA 526 in amanner similar to access by wireless device 516 via base station 514,ASN-GW 512, and visited CSN/AAA 524, a difference being that WiMAX CPE522 is generally disposed in a stationary location, although it may bemoved to different locations as needed, whereas wireless device may beutilized at one or more locations if wireless device 516 is within rangeof base station 514 for example. In accordance with one or moreembodiments, operation support system, self organizing networks (OSS(SON)) sever 536 may be part of network 500 to provide managementfunctions for network 500 and to provide interfaces between functionalentities of network 500. Network 500 of FIG. 5 is merely one type ofwireless network showing a certain number of the components of network500, however the scope of the claimed subject matter is not limited inthese respects.

Thus, described herein is an integrated transmit/receive switch whichmay achieve high power handling capability without the use of seriesswitches. In some embodiments the input power PI may be up to or greaterthan 38 dBm. In addition, the switch construction provides strongisolation (i.e., 35 dB) from the transmitter to the receiver and a lowinsertion loss (e.g., less than 1 dB). Further, the switch constructionprovides a high bandwidth response (i.e., greater than 15%) and operateswell at high frequencies (i.e., 6 GHz) and exhibits high pass responsein the receiver.

The terms “logic instructions” as referred to herein relates toexpressions which may be understood by one or more machines forperforming one or more logical operations. For example, logicinstructions may comprise instructions which are interpretable by aprocessor compiler for executing one or more operations on one or moredata objects. However, this is merely an example of machine-readableinstructions and embodiments are not limited in this respect.

The terms “computer readable medium” as referred to herein relates tomedia capable of maintaining expressions which are perceivable by one ormore machines. For example, a computer readable medium may comprise oneor more storage devices for storing computer readable instructions ordata. Such storage devices may comprise storage media such as, forexample, optical, magnetic or semiconductor storage media. However, thisis merely an example of a computer readable medium and embodiments arenot limited in this respect.

The term “logic” as referred to herein relates to structure forperforming one or more logical operations. For example, logic maycomprise circuitry which provides one or more output signals based uponone or more input signals. Such circuitry may comprise a finite statemachine which receives a digital input and provides a digital output, orcircuitry which provides one or more analog output signals in responseto one or more analog input signals. Such circuitry may be provided inan application specific integrated circuit (ASIC) or field programmablegate array (FPGA). Also, logic may comprise machine-readableinstructions stored in a memory in combination with processing circuitryto execute such machine-readable instructions. However, these are merelyexamples of structures which may provide logic and embodiments are notlimited in this respect.

Some of the methods described herein may be embodied as logicinstructions on a computer-readable medium. When executed on aprocessor, the logic instructions cause a processor to be programmed asa special-purpose machine that implements the described methods. Theprocessor, when configured by the logic instructions to execute themethods described herein, constitutes structure for performing thedescribed methods. Alternatively, the methods described herein may bereduced to logic on, e.g., a field programmable gate array (FPGA), anapplication specific integrated circuit (ASIC) or the like.

In the description and claims, the terms coupled and connected, alongwith their derivatives, may be used. In particular embodiments,connected may be used to indicate that two or more elements are indirect physical or electrical contact with each other. Coupled may meanthat two or more elements are in direct physical or electrical contact.However, coupled may also mean that two or more elements may not be indirect contact with each other, but yet may still cooperate or interactwith each other.

Reference in the specification to “one embodiment” or “some embodiments”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least animplementation. The appearances of the phrase “in one embodiment” invarious places in the specification may or may not be all referring tothe same embodiment.

Although embodiments have been described in language specific tostructural features and/or methodological acts, it is to be understoodthat claimed subject matter may not be limited to the specific featuresor acts described. Rather, the specific features and acts are disclosedas sample forms of implementing the claimed subject matter.

What is claimed is:
 1. A method to switch a transmit/receive modulecomprising a transmit network and a receive network between a receivestate and a transmit state, comprising: activating a connection in thereceive network to establish a high-impedance circuit in the receivenetwork by operating a first switch in the receive network to establishthe high-impedance circuit in the receive network to effectivelydecouple the receive network from the antenna; and coupling the transmitnetwork to the antenna; and operating a plurality of second switchesconnected in parallel in the receive network to isolate the receivenetwork from the transmit network.
 2. The method of claim 1, whereinoperating the plurality of second switches comprises closing theplurality of second switches to couple an amplifier of the receivenetwork to ground.
 3. The method of claim 1, further comprising:receiving signals from a power amplifier into the transmit network; andtransmitting the signals via the antenna.
 4. The method of claim 3,wherein transmitting the signals via an antenna comprises: opening asecond switch in the transmit module.
 5. A method to switch atransmit/receive module comprising a transmit network and a receivenetwork between a transmit state and a receive state, comprising:activating a connection in the transmit network to establish ahigh-impedance circuit in the transmit network by operating a firstswitch in the transmit network to establish the high-impedance circuitin the transmit network to effectively decouple the transmit networkfrom the antenna; coupling the receive network to the antenna; operatinga first switch in the transmit network to establish the high-impedancecircuit in the transmit network; receiving signals from an antenna intothe receive network; passing the signals to an amplifier; and operatinga plurality of secondary switches connected in parallel in the receivenetwork.
 6. The method of claim 5, wherein receiving signals from anantenna into the receive network comprises: opening a first switch in areceive network of the transmit receive module; and grounding aplurality of differential lines in the receive network.
 7. The method ofclaim 5, wherein operating the plurality of second switches comprisesclosing the plurality of second switches to couple an amplifier of thereceive network to ground.
 8. A method to transmit a signal from anelectronic device, comprising: switching a transmit/receive module inthe electronic device between a receive state and a transmit state by:activating a connection in the receive network to establish ahigh-impedance circuit in the receive network by operating a firstswitch in the receive network to establish the high-impedance circuit inthe receive network to effectively decouple the receive network from theantenna; and coupling the transmit network to the antenna; receiving aplurality of signals from a power amplifier into the transmit network;and transmitting the plurality of signals via the antenna; and operatinga plurality of second switches connected in parallel in the receivenetwork to isolate the receive network from the transmit network.
 9. Themethod of claim 8, wherein transmitting the signals via an antennacomprises: opening a second switch in the transmit module.
 10. A methodto receive a signal in an electronic device, comprising: switching atransmit/receive module in the electronic device between a transmitstate and a receive state by performing operations, comprising:activating a connection in the transmit network to establish ahigh-impedance circuit in the transmit network; and coupling the receivenetwork to the antenna; receiving signals from an antenna into thereceive network by: opening a first switch in a receive network of thetransmit receive module; and grounding at least two differential linesin the receive network by opening at least two secondary switches whichare connected in parallel in the receive network; and passing thesignals to a low noise amplifier.
 11. The method of claim 10, whereinactivating a connection in the transmit network to establish ahigh-impedance circuit in the receive network comprises: effectivelydecoupling the transmit network from the antenna.
 12. The method ofclaim 11, wherein decoupling the transmit network from an antennacoupled to the transmit/receive module comprises: closing a first switchin the transmit network to establish a high-impedance RLC circuit in thetransmit network.
 13. The method of claim 12, wherein closing the firstswitch in the receive network effectively decouples the transmit networkfrom an antenna.